Guard for pipe outlet



June 11, 1963 H. J. COMPTON 3,093,582

GUARD FOR PIPE OUTLET Filed Aug. 10, 1959 INVENTOR. HENRY J. COMPTON ATTOR NEHS United States Patent 3,093,582 GUARD FOR PIPE OUTLET Henry J. Compton, Casco Township, Allegan County, Mich. (Rte. 2, South Haven, Mich.) Filed Aug. 10, 1959, Ser. No. 832,785 2 Claims. (Cl. 210-463) This invention relates in general to a guard for an opening in a pipe and, more particularly, to a type of pipe guard adapted for removable reception into the exposed end of the outlet pipe for a system of drainage tiles.

It is essential in many rural areas to provide some fields, upon which crops are raised, with underground drainage system for removing excessive amounts of Water. In fact, it is so important in many regions that financial assistance is granted by governmental agencies for the purpose of installing such drainage systems. Usually, such drainage systems include a plurality of loosely connected tiles "arranged in rows spaced approximately four rods apart and disposed from 2 to 3 feet below the surface of the ground. The end of each row of tiles is usual ly connected to an outlet pipe which opens into a drainage ditch. Obviously, it is essential that the outlet pipe be maintained free of obstructions in order to permit the free flow of the water into the drainage ditch.

It has been found that small animals, such as muskrats, will crawl into unguarded outlet pipes and till them with foreign materials which obstruct the flow of water from the drainage system. Moreover, a high water level in the drainage ditch may cause such materials to back up into the drainage system having an unguarded outlet pipe.

In order to overcome this problem, various types of guards have been provided, but such guards have not been entirely satisfactory for a variety of reasons. For example, many of the existing guards are permanently secured to the drain pipe and, therefore, require a large inventory of different pipe sizes to fit differing needs. Also, permanent guard structures are difficult to clean, if they become plugged with debris, and they are difiicult to replace or repair Without removing the entire outlet pipe, which is usually a major operation.

Existing types of removable pipe guards are often difficult to hold in position or are expensive to provide and costly to maintain and, in many instances, are incapable of properly guarding the outlet end of the drain pipe. That is, they do not always prevent the entry of the animal s and/ or the foreign materials.

Generally speaking, most of the presently used types of outlet pipes for drainage systems are corrugated in order to provide the necessary rigidity and resistance to radial collapse. Sometimes these corrugations are in the form of uniformly spaced constrictions in the pipe and in some instances the corrugations may be in the form of spirals.

While considering existing guards for this purpose, it became apparent that an improved type of guard was clearly needed. It also became evident that such a guard should be sturdy but light in weight, inexpensive to fabricate, durable under severe weather conditions, inexpensive to produce, easy to install, consisting of a structure adaptable to various types of pipe sizes and capable ofinsta-llation in both corrugated and smooth bore types of pipes.

Accordingly, a primary object of this invention has been the provision of a guard for the outlet pipe of a drainage system, which guard insures the free flow of water through the outlet pipe without interference from accumulations of foreign materials in the outlet pipe resulting from the usual causes.

A further object of this invention has been the provision of a guard, as aforesaid, which is inexpensive to manufacture, which is sturdy in construction, and which is ex- ICC? tremely easy to install in a corrugated, metal outlet pipe of any conventional type, including the type of pipe having spiral corrugations.

A further object of this invention has been the provision of a guard, as aforesaid, having a structure which can be easily adapted to various types and sizes of outlet pipes and which requires no permanent connections to the pipe with which it is used.

Other objects and purposes of this invention will become apparent to persons familiar with this type of equipment upon reading the following specification and examining the accompanying drawings, in which:

FIGURE 1 is an end elevational view of a corrugated pipe containing a guard embodying the invention.

FIGURE 2 is a sectional view taken along the line II-II in FIGURE 1.

FIGURE 3 is a perspective view of the guard shown in FIGURE 1.

FIGURE 4 is a top view of said guard.

FIGURE 5 is a perspective view of an alternate guard construction embodying the invention.

FIGURE 6 is a top view of the alternate guard shown in FIGURE 5, as appearing in another type of corrugated pipe.

FIGURE 7 is a top view of a modified guard structure shown with, and adapted for, a further type of corrugated pipe.

For convenience in description, the terms upper, lower, front, rear and derivatives thereof will have reference to the guard as appearing in FIGURE 1. The terms inner, outer, and derivatives thereof will have reference to the geometric center of the guard structure and the pipe associated therewith.

General Description The objects and purposes of the invention, including those set forth above, have been met by providing an improved guard structu-re for the outlet pipe of a drainage system. The guard is comprised of a grill and integral positioning elements secured to said grill and extending in substantially the same direction away from the plane defined by the grill for holding the grill within a drain pipe in a position where said plane is substantially perpendicular to the lengthwise extent of the pipe. In one preferred embodiment of the invention, the guard structure is produced from a single piece of rod which is appropria-tely bent to form the grill and the support arms. The support arms are arranged and shaped so that their free ends will engage the corrugations in a conventional type of corrugated pipe with which said guard is normally used, thereby preventing accidental displacement or the guard lengthwise of the pipe.

Detailed Construction The guard 10 (FIGURES 2 and 3), which has been selected to illustrate one preferred embodiment of the invention, is comprised of a grill 11 and a pair of positioning arms '12 and 13 which are preferably integral with said grill. The guard 10 in intended to be used in association with a substantially cylindrical, corrugated pipe 16 (FIGURE 2), which may be of a conventional type, such as the pipe used at the outlet end of a drainage system. More specifically, the outlet pipe '15 may be fabricated from sheet metal and is corrugated for the purpose of resisting radially inwardly applied forces. The corrugations 17 in the pipe 16 are in the form of double spirals having inwardly extending ridges 18 which separate adjacent convolutions of the spirals. It will be seen,

and discussed hereinafter, how the guard structure 10 can be used in a pipe '15 having circular corrugations 20 and separating ridges 19.

The corrugation-s 17 and 20 are reasonably shallow so that they do not materially obstruct the free flow of water 3 through the drain pipe. As seen in FIGURES 2 and 6, the scallops 22 and 23 between adjacent ridges '18 and 19, respectively, are diametrically aligned. That is, the opposite ends of any diameter in the pipes '15 and 16 will engage corresponding parts of the scallops 22 and 23. The significance of this arrangement of the ridges and scallops in the cross-sectional contour of the pipes will become apparent hereinafter.

The grill 11 (FIGURES 1 and 4), is comprised in this particular embodiment, of three elongated, parallel grill elements 30, 31 and 32. The lower ends of elements 30 and 31 and the upper ends of elements 31 and 32 are interconnected by curved connection elements 33 and 34. The grill elements 30, 3.1 and 32 and the connection elernents 33 and 34 are all preferably part of, and formed from, a single rod having a substantially uniform cross section throughout its length. However, it will be apparent that the connection elements may be separate pieces which are welded or otherwise secured to the grill elements. The grill elements and connection elements are preferably circular in cross section, but may have other cross-sectional shapes if desired. The central axes of the grill elements and connection elements preferably, but not necessarily, lie substantially within a single plane.

The positioning arms 12 and 13, in this particular em bodiment, are preferably integral with the ends 35 and 36 of the grill elements 30 and 32, respectively, which ends are remote from the connection elements 33 and 34-. Moreover, said arms 12 and 13 are preferably resiliently flexible and extend substantially perpendicularly from the plane defined by the grill 11. The grill 11 and arms 12 and 13 may be fabricated from any suitable material including metal or a plastic material. The ends 35 and 36 of the grill elements 39 and 32 and portion of the outer surfaces of the connection elements 33 and 34 are preferably substantially tangent to a circle indicated by the broken line 37 in FIGURE 3. Thus, the arms 12 and 13 extend from said grill at points on diametrically opposite sides of the circle 37.

The outer end portions 38 and 39 of the arms 12 and 13 are bent away from each other, in directions radially outwardly of said circle 37, a distance approximately equal to the depth of the scallops in the pipe15 or 16. As shown in FIGURE 2, the arms 12 and 13 may be ofi'set inwardly at 42 and 43 adjacent to the grill 11 so that the adjoining portions, the arms 12 and 13 and grill elements 30 and 32 can be received into the scallops in pipes 15 and 16.

Where the guard is intended for use with a pipe 16 having diametrically aligned scallops 22 the positioning arms 12 and 13 preferably both extend from said grill 11 a distance about equal to the axial length of an even number, here two, of scallops 22. Thus, as shown in FIGURE 2, the end portions 38 and 39 on the arms 12 and 13 are received into one scallop or pair of seallops and the offset ends 42 and 43 are also received into a scallop or scallops which, in this em bodiment, are not adjoining the first-mentioned scallops. The distance between the end portions 38 and 39 is preferably about equal to the maximum inside diameter of the pipe 16. The diameter of the circle 37 defined by the outer edges of the grill 11, as stated above, is preferably slightly larger than the minimum inside diameter of the pipe 16 and somewhat smaller than the maximum inside diameter of the pipe 16.

Where the guard 10 is designed for a pipe 15, said circle 37 is preferably about equal to the minimum inside diameter of the pipe and the distance between the end portions 38 and 39 is larger than the minimum internal diameter of the pipe 15.

Where the guard is designed for use with a pipe 15, the length of the positioning arms does not have to correspond to any particular distance along the pipe, but said arms must be long enough to give proper support of the guard.

Usually the arms are equal in length to the combined axial length of two of the scallops 27.

Operation The guard 10 is installed in a pipe 16 (FIGURE 2), which has double spiral corrugations 17, by inserting the end portions 38 and 39 of the arms 12 and 13, respectively, into the end of the pipe. As shown in FIGURE 1, the starts of the two spiral corrugations are diametrically opposite each other just as the end portions 38 and 39 are with respect to the circle 37. Under some circumstances, the positioning arms 12 and 13 may be sprung outwardly away from each other slightly so that the distance between the remote surfaces on the end portions 38 and 39 is slightly greater than the maximum internal diameter of the pipe 16. Accordingly, the outer ends of the arms 12 and 13 are sprung toward each other as they are inserted into the pipe 16. Such distortion of the arms 12 and 13 may be utilized to increase the gripping effect of the arms within the pipe. When the end portions 38 and 39 have been positioned within the spiral corrugations 17, the guard 10 is fully inserted into the pipe by rotating it in the direction of the spiral corrugations. This can be accomplished by manually grasping the center grill element 31 and twisting it around the axis of the circle 37, which causes the end portions 38 and 39 to engage the spiral ridges 18 and thereby draw the guard 10 into the pipe.

When the grill 11 reaches a point adjacent to the end of the pipe 16, the ends 35 and 36 of elements 30 and 32 will be in such a position or relationship with respect to the corrugations 17 that they will in turn be received into the starting ends thereof. Thus, by continuing the rotation of the guard 10, it will be advanced along the spiral ridges 18 into the pipe 16. Where the connection elements extend beyond the minimum internal diameter of the spiral ridges 18, it is necessary for them to be offset with respect to the ends 35 and 36 of elements 30 and 32 along the axis of the circle 37 so that they will be received into the corrugations 17.

Accordingly, it will be seen that accidental dislodgment of the guard 10 from within the pipe 16 is positively prevented not only by the end portions 38 and 39 on the positioning arms 12 and '13 but also, under some circumstances, by the ends 35 and 36 of elements 36 and 32 and by the connection elements 33 and 34.

When it becomes desirable to remove the guard 10 from the pipe 16, such can be effected by rotating the guard 10 in the direction which is opposite to its rotational direction during the insertion of the guard. Because of the fact that the grill 11 can be located any place within the pipe 16 from one end thereof to the other, it can be adapted to any length of pipe. By springing the positioning arms 12 and 13 outwardly or inwardly, the guard 10 can be adapted to pipes which are slightly smaller or slightly larger than the size for which they have been constructed, providing only that the maximum inside diameter of the grill is not less than the diameter of the circle 37. Additional arms may be secured to the grill 11, if needed, between the arms 12 and 13.

Alternate Structures Where is becomes desirable to use the guard structure of the invention in a pipe which is substantially larger in diameter than the pipe 16, such may be accomplished by adding additional grill elements and positioning arms, as shown in FIGURES 5 and 6. More specifically, the alternate guard 46 has four grill elements 47 which preferably lie within a single plane and are connected at alternate adjacent ends by the connection elements 48, to form a grill 49 in substantially the same manner as set forth above with respect to the grill 11. The alternate guard 46 includes a pair of positioning arms 52 and 53 which are integral with, and extend substantially perpendicularly from the plane defined by, the grill elements 47. A third positioning arm 54 is secured, as by Welding, to the grill 49 at a point intermediate the positioning arms 52 and 53, so that it extends in a direction substantially parallel with the positioning arms 52 and 53. In this particular embodiment, the positioning arm 54 is secured to one of the connection elements 48.

The outer ends of the positioning arms 52, 53 and 54 have end portions 56 which curve radially outwardly with respect to the circle 57 (FIGURE 5) defined by the outer edges of the grill 49. Where the guard 49' is used in conjunction with a pipe having circular corrugations circle 57 has a diameter which is not greater than the minimum internal diameter of the pipe 15, as defined by the circular ridges 19. However, the distance between the remote surfaces of the end portions 56 of the positioning arms is preferably equal to or slightly larger than the maximum inside diameter of the pipe 15. Moreover, the positioning arms 52, 53 and 54, which may be resiliently flexible, preferably extend substantially equidistantly from the grill 49.

The alternate guard 46 is installed by inserting the positioning arms 52, 53 and 54 into the end of the pipe 15 and then by pressing firmly against the outer surface of the grill 49, so that the guard 46 is forced into the pipe 15. Due to the resilience of the positioning arms 52, 53 and 54, they will be flexed inwardly as their end portions 56 pass over the circular ridges 19. The engagement between the end portions 56 and the adjacent circular ridges 19 will prevent accidental dislodgment of the guard 46 from its desired position within the pipe 15. As in the case of the guard 18, the alternate guard 46 can be disposed any place lengthwise of the pipe 15 in which it is used.

If it becomes desirable to use the alternate guard 46 with a pipe, such as the pipe 24, having single spiral corrugations 26, then it may become necessary to alter the length of the positioning arms 52a, 53a and 54a whereby a modified guard 46a is produced. More specifically, by shortening some of the positioning arms 52a, 53a, and 54a, the end portions 56a thereof will be located with respect to the grill 49a so that said end portions will be properly disposed between spiral ridges 26 when the grill 49a is substantially perpendicular to the lengthwise axis of the pipe 24. The modified guard 46a is installed in a pipe 24 by rotating the guard 46a in substantially the same manner set forth above with respect to the guard 10.

Where performance which meets some but not necessarily all of the objects and purposes of this invention will be acceptable, any one of the guards 1t 46 and 46a may be used in conjunction with a smooth bore pipe having an inside diameter substantially equal to the diameter of the circle 37 or the circle 57. In such case, positioning of the guards within the smooth bore pipe is effected by springing the positioning arms on the respective guards so that they press firmly against the inner wall surfaces of the pipe.

It will also be apparent from the above description that grills may be provided with additional grill elements in 6 any desired quantity, depending upon the use to which the guard will be put. Moreover, the number of positioning arms used in connection with any guard is not limited except that at least two arms are required.

Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be understood that variations or modifications of such disclosure, which lie within the scope of the appended claims, are fully contemplated.

What is claimed is:

1. A guard structure for the lengthwise opening in a corrugated pipe of substantially circular cross-section, comprising:

wall means defining the opening in the pipe, said wall means having a plurality of adjacent, similar and substantially annular recesses communicating with said opening;

a grill formed from substantially rigid rod means, said grill having at least three, elongated, spaced and substantially parallel rod elements substantially disposed within the same plane, and at least two arcuate elements disposed substantially within said plane, each pair of adjacent rod elements being rigidly secured at adjacent, corresponding ends thereof to the opposite ends of one of said arcuate elements, and said two arcuate elements being located at the opposite ends of said rod elements, the outer edges of said two arcuate elements and one end of both of the two outermost rod elements being substantially tangent to the periphery of a circle disposed substantially within said plane and having substantially the same diameter as said annular recesses;

a pair of gripping arms rigidly secured to and extending away from the two outermost rod elements near the said one ends thereof in a direction substantially perpendicular to said plane, said arms being on the same side of said plane and having end portions extending into said recesses.

2. The structure of claim 1 wherein said corrugated pipe has a spiral corrugation of which said annular recesses are adjacent revolutions of the spiral; and

wherein said end portions of said gripping arms are located at different distances from said plane.

References Cited in the file of this patent UNITED STATES PATENTS 364,823 Ingold June 14, 1887 380,873 Drendul Apr. 10, 1888 767,471 Barnett Aug. 16, 1904 2,136,755 Prince Nov. 15, 1938 2,286,231 Schmitt June 16, 1942 2,647,636 Rafferty Aug. 4, 1953 2,690,064 Rupe Sept. 28, 1954 2,766,889 Rey Oct. 16, 1956 FOREIGN PATENTS 804,445 France Aug. 3, 1936 

1. A GUARD STRUCTURE FOR THE LENGTHWISE OPENING IN A CORRUGATED PIPE OF SUBSTANTIALLY CIRCULAR CROSS-SECTION, COMPRISING: WALL MEANS DEFINING THE OPENING IN THE PIPE, SAID WALL MEANS HAVING A PLURALITY OF ADJACENT, SIMILAR AND SUBSTANTIALLY ANNULAR RECESSES COMMUNICATING WITH SAID OPENING; A GRILL FORMED FROM SUBSTANTIALLY RIGID ROD MEANS, SAID GRILL HAVING AT LEAST THREE, ELONGATED, SPACED AND SUBSTANTIAL PARALLEL ROD ELEMENTS SUBSTANTIALLY DISPOSED WITHIN THE SAME PLANE, AND AT LEAST TWO ARCUATE ELEMENTS DISPOSED SUBSTANTIALLY WITHIN SAID PLANE, EACH PAIR OF ADJACENT ROD ELEMENTS BEING RIGIDLY SECURED AT ADJACENT, CORRESPONDING ENDS THEREOF TO THE OPPOSITE ENDS OF ONE OF SAID ARCUATE ELEMENTS, AND SAID TWO ARCUATE ELEMENTS BEING LOCATED AT THE OPPOSITE ENDS OF SAID ROD ELEMENTS, THE OUTER EDGES OF SAID TWO ARCUATE ELEMENTS AND ONE END OF BOTH OF THE TWO OUTERMOST ROD ELEMENTS BEING SUBSTANTIALLY TANGENT TO THE PERIPHERY OF A CIRCLE DISPOSED SUBSTANTIALLY WITHIN SAID PLANE AND HAVING SUBSTANTIALLY THE SAME DIAMETER AS SAID ANNULAR RECESSES; A PAIR OF GRIPPING ARMS RIGIDLY SECURED TO AND EXTENDING AWAY FROM THE TWO OUTERMOST ROD ELEMENTS NEAR THE SAID ONE ENDS THEREOF IN A DIRECTION SUBSTANTIALLY PERPENDICUALR TO SAID PLANE, SAID ARMS BEING ON THE SAME SIDE OF SAID PLANE AND HAVING END PORTIONS EXTENDING INTO SAID RECESSES. 